We had a take-home quiz and me and my friend were arguing over a certain problem, I need to know the correct answer because I need to show it to him on Monday, can somebody please help me out, thank you to the person who does:
Brittany stands at rest on a skateboard. The combined mass of Brittany and the skateboard is 50 kg . Dave tosses a 3.7-kg pumpkin to Brittany, and when she catches it, she and the skateboard begin to roll backward with a speed of 0.12 m/s .
What was the speed of the pumpkin?
Physics Argument?
2016-02-06 7:56 pm
回答 (2)
2016-02-06 9:52 pm
✔ 最佳答案
Since the initial momentum is 0, the sum of the final momentums is 0.Total mass = 50 + 3.7 = 53.7 kg
Final momentum = 53.7 * -0.12 = v = -6.444
This momentum is negative, because Brittany and the skateboard are moving backward.
For the pumpkin, initial momentum = 3.7 * v
3.7 * v + -6.444 = 0
v = 6.444/3.7
This is approximately 1.74 m/s.
2016-02-06 8:22 pm
Hint:
conservation of momentum
conservation of momentum
收錄日期: 2021-04-21 16:43:33
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160206115631AA1mKWy